Pre-KSR obviousness instruction does not result in plain error post-KSRJanuary 10, 2008

In a decision this week, the Federal Circuit affirmed findings of infringement of two patents by two defendants. The court also reversed an invalidity ruling of one of one claim that had been the subject of reexamination, but remanded the case to the district court for a determination of the obviousness of one claim based on a revised claim construction and for a determination of damages.While the case went to the jury pre-KSR, the court held that the district court's jury instructions on obviousness, which focused on the teaching-suggestion-motivation test, including that a motivation to combine references may be found in the nature of the problem to be solved, did not warrant reversal. This indicates that the effect of KSR on the obviousness analysis may not be as dramatic as some have predicted, at least outside the USPTO.In addition, the court held that the requirements in 35 U.S.C. § 305 regarding new claims in reexamination proceedings need not be specifically noted by the applicant when adding new claims. Instead, the court confirmed that the limit on new and amended claims in reexamination is that they may not enlarge the scope of the original claims.More detail of Cordis Corp. v. Medtronic AVE, Inc. after the jump.

These consolidated appeals are between competing manufacturers of coronary stents, and relate to two patents, 4,739,762 and 5,195,984. The '762 patent discloses a coronary stent mountable on an angioplasty balloon and delivered to a target location intraluminally via catheter. At issue is claim 23, which covers an expandable intraluminal vascular stent comprising a "tubular member having . . . a wall surface . . . the wall surface having a substantially uniform thickness and a plurality of slots formed therein." The claim also requires the wall surface to be "smooth." The '984 patent discloses a flexible stent manufactured by joining tubular members by a connector providing "necessary flexibility to negotiate the bends and curves in tortious body passageways, such as the vascular system." Cordis is the owner of the patents, and brought suit against Medtronic AVE and Boston Scientific for infringement. Cordis first alleged that three of Medtronic's stents infringed the patents. A jury found in favor of Cordis, deciding that Medtronic's stents did infringe the patents under the doctrine of equivalents. However, the district court granted Medtronic's motion for judgment as a matter of law of non-infringement under the doctrines of equivalents and granted a new trial on the issue of literal infringement. In a previous appeal, the Federal Circuit reversed the district court's construction of the claim "plurality of slots formed therein" and "substantially uniform thickness," holding that the slots did not require a particular formation process and that the district court erred in narrowly construing the "uniform thickness" limitation. The Federal Circuit construed the term "substantially uniform thickness" to mean that the "walls must be of largely or approximately uniform thickness" as based on the prosecution history showing that Cordis had previously disclaimed stents having varying thickness of its walls. On remand, the jury found infringement based on the revised construction, and Medtronic appealed again. Medtronic argued that its stents fail to meet the "substantially uniform thickness" limitation because its walls diminish in thickness in the tapered end of the crown portion of the device. A diagram of the Medtronic stent is shown below, with the "crown" portion circled:Medtronic stentMedtronic argued that based on the Federal Circuit's construction in the previous appeal, its stents could not infringe because the thickness of the stent decreased to zero at the tip of the "crowns" on the stent. The Federal Circuit disagreed, finding this method of measuring the thickness of the stent inconsistent with its earlier construction. The court held that the jury's verdict of infringement of this limitation was supported by substantial evidence, and therefore affirmed this finding. Medtronic also argued that it was entitled to judgment as a matter of law of noninfringement of the '984 patent because its stents do not meet the "flexibly connect" limitation. Medtronic argued that its stents' connectors were not flexible, and therefore did not meet this limitation. The Federal Circuit disagreed, noting that the claim language only required that the stent itself be flexible, not that the connectors be flexible in and of themselves. Medtronic also took issue with one of Cordis's experts who testified at trial as to the simulated bending in Medtronic's stents to meet the "flexibly connect" limitation, arguing that the testimony should have been excluded as unreliable. The Federal Circuit disagreed, noting the expert had a doctoral degree in mechanical engineering and extensive experience, and was therefore adequately qualified under Rule 702. Moreover, Medtronic had adequate opportunity to present their concerns about the data and the expert to jury. Medtronic further contended it was entitled to a new trial on several grounds, but the Federal Circuit rejected these challenges as well.

A final challenge that Medtronic presented related to the district court's instruction to the jury on obviousness, alleging that it conflicted with KSR, which was decided between the time the instruction was given and the time of the appeal. The instruction was as follows, in relevant part:

A suggestion to combine references may also flow from the nature of the problem or from the ordinary knowledge of those skilled in the art that certain references are of special importance. If the prior art references as a whole do not teach, suggest or motivate that combination, then they may not be combined. The mere fact that the prior art can be modified does not make the modification obvious unless the prior art suggests the desirability of the modification.

The Federal Circuit stated that

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